The present invention relates to a rear view mirror assembly of a vehicle, and more particularly to improvements in a base member for installing the rear view mirror assembly on a windshield of a vehicle.
The following U.S. Patent Applications are contemporaneous with this application and disclose rear view mirror assemblies:
U.S. patent application Ser. No. 756,950, filed July 19, 1985 PA1 U.S. patent application Ser. No. 756,953, filed July 19, 1985 and PA1 U.S. patent application Ser. No. 756,952, filed July 19, 1985. The disclosure of each of the above-identified applications is herein incorporated by reference.
An adjustable device disposed between a base member and a support arm of a rear view mirror is disclosed in Japanese Utility Model Laid-open No. Showa 58-24595. In this Japanese Utility Model Laid-open No. Showa 58-24595, the rear view mirror includes a support arm, a spring and a base member. The base member is cemented on an interior of a windshield, and includes a bar and a mounting portion. The spring includes a hooked end and a rear edge, and the hooked end being mounted on the bar of the base member. The rear edge of the spring is disposed on the mounting portion, and the support arm is fixed on the spring by a bolt.
Further, the base member includes a slanted surface on a bottom surface thereof and the support arm includes an incline on an end thereof. As shown in FIG. 12 of Japanese Utility Model Laid-open No. Showa 58-24595, when a force "Pc" is applied to the rear view mirror, the support arm is moved downwardly and breaks away, because the incline of the support arm and the slanted surface of the base member prevent the support arm from resisting the force "Pc".
Furthermore, this rear view mirror assembly includes a spherical ball portion disposed on an opposite end of the support arm, the ball portion being received within a socket portion of the rear view mirror.
Therefore, this rear view mirror can be adjusted to its angle through the spherical ball portion and the socket portion of the rear view mirror. However, the range of the adjustment of this rear view mirror is rather small, because this rear view mirror includes only one adjustment device. In addition, it is not easy for a worker to install the components of the rear view mirror because the worker must install the nut of the spring into the hole of the support arm and then fix the support arm on the spring with a bolt. Such installment procedures are cumbersome and complex.
A suitable material for a base member for mounting a rear view mirror assembly is disclosed in Japanese Utility Model Application Laid-open No. Showa 57-29443. In this publication, the suitable material is sintering stainless steel which has a similar coefficient of thermal expansion to a coefficient of thermal expansion of a windshield. That is, the base member which is made of sintering stainless steel expands at a similar rate of expansion as the windshield heated by the sun. In the publication Laid-open No. Showa 57-29443, the coifficient of thermal expansion of the windshield is 9.times.10.sup.-9 mm/mm/.degree.C., and the coefficient of thermal expansion of the base member which is made of the sintering stainless steel is from 9.times.10.sup.-6 mm/mm/.degree.C. through 12.times.10.sup.-6 mm/mm/.degree.C.
Generally, sintering stainless steel has many pores therein, and the base member which is made of the sintering stainless steel is cemented to the windshield through an adhesive. Therefore, pores exist between the adhesive and a contact surface of the base member, and air exists in each of the pores. When the sun heats the windshield and the base member, the air expands in the pore and tends to separate the base member from the windshield in spite of the adhesive.
Accordingly, air passages are formed between the adhesive and the contact surface of the base member, and the adhesion of between the windshield and the base member is weakened by the air passages.